Next it was time to shoot the stars in action: "We shot Pharrell and N.E.R.D. in a studio in L.A. and Julian and Santogold in a studio in NYC. We needed to design a stage for the artists to move around, to perform and do their thing, but also perform certain moves that we designed and planned for some scenarios. we built a big white "playground" with some objects like stairs, boxes and a punching bag for them to react to and interact with," says Spier.

They used a setup with three HD cameras shooting simultaneously from different angles, to allow for transitions and changing perpectives. "This also allowed us to be most efficient and flexible since time with our artists was precious and we didn't know what to expect," says Spier. "Then we edited the best takes together and handed the footage over to our compositors to define a style of the footage. They colour-corrected to a black and white photocopy grade and dropped frames to create a subtle jitter in the footage."

Next came the painstaking step of rotoscoping all the footage: each artist needed to be 'cut out', frame by frame. "There were over 150 shots to cut out," says Spier. "Eeek. That’s a lot of roto – even Jen, our producer, roto-ed a few shots."

Now that the performers had been transformed into CG 'paper dolls', it was time to transport them into 3D space, animate them and carefully link together the sequence into a single camera move, before lighting them and compositing them in CG. "I believe there were about 9,580 paper dolls all together in the music video and it took 30 animators for two months to complete the project," says Hyon.

The team used Softimage|XSI, Flame, Avid and Photoshop – but also list "paper, scissors, Exacto knife, glue stick, desk lamp" as among the tools they used.

The promo was an unusual project for Psyop: "It is unusual for us to go into a shoot not knowing exactly how the final spot would play out," says Hyon. "We are usually very particular in our planning process, we plan every little detail of the shoot, especially the story or the journey aspect. On this job, we could not do our normal anal retentive planning. Because of the nature of the collaboration between the three artists, we did not have a track until the day of the shoot and the parts were being moved around and finalized, so we could not really create a story line. So rather than force fitting a story, we thought to bring it back to the concept of ‘connectivity’ in a paper world and be spontaneous about it. Have Pharrell, Santi, Julian and N.E.R.D. guys perform the song in their very unique individual ways and to let that be a guide for us."

"This was very nerve-racking experience for us but we welcomed the unique challenge it presented," she continues. "In the end we like the more loose approach to shooting, it really paid off by capturing some really great spontaneous actions."